Types of intellectual disability (and characteristics)
A classification of low IQ ranges, with their characteristics and limitations.
Oligophrenia, mental retardation, intellectual disability... all these words refer to the same concept, with which we refer to those people who have lower cognitive resources than expected for their chronological age. People with one of the types of intellectual disabilities.
This type of disability generally causes severe difficulties in adapting to the environment, unless they are given a sufficient level of help. But intellectual disability is not unique and homogeneous in all people who suffer from it, but we can find different types or grades depending on the degree of functional impairment and IQ level..
Normal distribution and intelligence
Intelligence is a construct that refers to the individual's capacity to be able to adapt to the environment and to solve the situations he/she and resolve the situations he/she encounters. Regardless of how it is viewed within the multiple theories on the subject, different people will be organized in different ways and their mental capacities will be affected by different reasons and variables. Each of us has a specific and distinctive degree of ability or capacity in different areas and skills, including the ability to solve problems and adapt to the environment.
In order to assess the level of intelligence of the population the IQ level has traditionally been used, understood as the ratio of mental age to mental age.understood as the relationship between mental age and chronological age of the individual to be assessed. Taking into account that there is a great variability in the scores reflected by the population as a whole, it is necessary to take into account that a certain dispersion of scores around the mean is always to be expected. This expected dispersion is conceptualized as standard deviation.
Statistically, intelligence follows a normal distribution. That is, if we score the cognitive abilities of a population with an intelligence test, a large majority of people would have a normal distribution, a large majority of people would have scores very similar to each other while few individuals would have scores very similar to each other while a few individuals would have scores far from the majority. People with such scores, far from the majority, could either score higher or lower.
Since the mean IQ is set at a value of 100 and the standard deviation is 15, values that are at least two standard deviations away are considered normative. If these two deviations are above, we would be talking about giftedness, while if values two standard deviations are above, we would be talking about giftedness. if the values are two standard deviations below the mean, we are talking about a level of intelligence corresponding to a level of intelligence corresponding to a level of intelligence corresponding to the mean. we will be talking about a level of intelligence corresponding to intellectual disability.
Types of intellectual disability
The intellectual disability is understood as a condition in which the people who suffer it have severe limitations and deficiencies in the intellectual functioning, having problems in the reasoning, the planning, the resolution of problems or the learning.
In addition, these people have deficiencies in adapting to the environment, requiring assistance in one or more dimensions of human functioning so that their daily life is not limited in their personal autonomy and social participation. their daily life is not limited in their personal autonomy and social participation.. It is categorized as a neurodevelopmental disorder, being necessary that these difficulties are observed during development.
However, this is not a totally homogeneous category, and that is why different types of intellectual disability have been established according to the degree to which they deviate from the average.
Different degrees of disability
Cognitive abilities are important to be able to respond efficiently to the demands of the environment. Thus, people who have a reduced capacity in this type of skills will find it difficult to cope with situations that arise throughout their lives.
Depending on the level of difficulty encountered by these people in their daily lives and the level of IQ reflected by intelligence tests, the existence of several groups, types or degrees of intellectual disability has been considered..
However, it must be taken into account that the degree of IQ is not an absolute measure, but a relative one; it always depends on a reference group, since the IQ indicates the position that the person occupies in the distribution of scores obtained. Therefore, by changing the reference group a score can be within the normal range of intelligence or in what is considered to be intellectual disability. IQ indicates individual differences between people, but to actually measure a person's true cognitive abilities accurately there are other tools and methods.
1. Mild
A mild or slight intellectual disability is considered to be a disability of persons with an Intellectual Quotient between 50 and 70corresponding to two standard deviations below the population average. Most people with intellectual disabilities (approximately 85%) are at this level.
People with this degree of intellectual disability have mainly a delay in the cognitive domain and a slight impairment in the sensorimotor domain.. Learning abilities are slightly delayed, but they are able to remain in the educational system, to be trained and to exercise a professional activity adequately. They are able to read, write and perform calculations, although they usually require a longer learning period than others. In fact, it is possible that during preschool they do not differ much from their peers.
Some problems in memory, executive functions and abstract thinking may be observed. Their communication and social skills may be good, although they usually show some difficulty in detecting social cues and regulating their emotions and behavior. They are mostly autonomous individuals, requiring social guidance in specific situations, and help with legal, financial or parenting issues. Although they need support, their adaptation to the environment is usually satisfactory.
Moderate
In this degree of intellectual disability the difficulties are greater. At the educational level they can usually benefit from specific job training, generally in order to perform unskilled work and with supervision. They can have autonomy in self-care and movement..
The conceptual abilities of these subjects develop very slowly, with a great difference with respect to the peer group. They usually need help when the tasks to be carried out require processing complex concepts. Their communication is socially efficient, although not very complex. The subject is able to establish relationships with the environment and make new links with people outside the family.
Although they may have problems following social conventions, they generally adapt well to community life, especially with supervision. The individual can take responsibility for his or her own decisions and participate in social life, albeit with assistance and with a prolonged learning period.
Individuals with a moderate degree of intellectual disability usually reflect an IQ of between 35-50.
3. Severe
With an IQ between 20 and 35The problems for people with this level of disability are generally of great importance, requiring assistance and continuous supervision. Many of them have neurological damage..
At a conceptual level, the abilities of people with this degree of intellectual disability are reduced, having little understanding of reading and numerical concepts. Communicatively language is possible but is limited, focusing on the present and frequently using holophonic and frequently using holophrases or single words. They understand simple gestural and oral communication, being the relationship with loved ones a source of joy.
In day-to-day activities these subjects always need to be supervised and cared for, depending on aids and custodians. They can learn to speak and perform simple tasks. Their adaptation to the community can be good unless they have some other associated disability. Acquiring skills is possible, needing constant help and a long learning process.. Some of them self-injure. At the legal level they are considered incapable of making their own decisions.
4. Profound
The highest degree of intellectual disability and also the most infrequent, people with this level of disability have an IQ below 20. They need constant care, having very few options unless they have a very high level of help and supervision. Their survival rate is generally low.
Most of them have severe handicaps and other severe disabilities, as well as major neurological problems. At the conceptual level these people use mainly physical concepts and have severe difficulties in using symbolic processes. severe difficulties in using symbolic processes. The use of objects for self-care, work or leisure is possible but it is frequent that other alterations prevent them from giving them a functional use. At the sensorimotor level they are very limited, as well as at the communicative level.
Regarding communication and social skills, they can understand instructions and gestures, but they must be simple and direct. Emotional expression is mainly through direct non-verbal communication, without symbolism. They enjoy relationships with familiar people. On a practical level, the subject will be dependent for most activitiesalthough they can help in some activities, making it possible for them to participate in daily life at home and in society.
The need for assistance
As a conclusion of this article, it is relevant to mention that a person is only disabled to the extent that he/she has a disability. is only disabled to the extent that he/she does not have the tools to adapt to the environment.The most common problem is the lack of support to help them solve their difficulties. In this sense, intellectual disability is no exception. We can not just point out that someone has an intellectual disability and limit the problem to the individual; society has much to say when it comes to changing the living conditions of these people in vulnerable situations.
Work must be done from different disciplines (psychology, judicial field, legislative field, education and social assistance, among others) so that these people and the people who care for them can participate in an active way in the social life of the community, establishing bridges between the capabilities of each individual and what society can offer and demand through the granting of specific and functional aids.
Bibliographical references:
- American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders. Fifth edition. DSM-V. Masson, Barcelona.
(Updated at Apr 13 / 2024)